Electric slow-down device.



D. L. LINDQUIST.

ELECTRIC SLOW DOWN DEVICE.

APPLICATION FILED 11.13.17, 1910.

1, 1 09,850, Patented Sept. 8, 1914.

3 SHEETSSHEET 1.

3 Woe ntoz D. L. LINDQUIST. ELECTRIC SLOW DOWN DEVICE. APPLICATION FILED FEB.17,1910,

1,109,850, Patented Sept. 8, 1914.

3 SHEETSSHEET 2.

3 vvue Wtoz:

/ vil D. L. LINDQUIST. ELECTRIC SLOW DOWN DEVICE.

Patented Sept. 8, 1914.

APPLICATION FILED FEB. 17, 1910.

3 SHEETSSHEET 3.

45 M iguan UNITED STATES PATENT OFFICE.

DAVID L. LINDQUIST, OF YONKERS, NEW YORK, ASSIGNOR TO OTIS ELEVATOR COMPANY, OF JERSEY CITY, NEW JERSEY, A CORPORATION OF NEW JERSEY.

ELECTRIC SLOW-DOWN DEVICE.

Specification of Letters Patent.

Patented Sept. 8, 1914.

To all whom it may concern:

Be it known that I, DAVID L. LINDQUIST, a subject of the King of Sweden, residing at Yonkers, in the county of \Vestchester and State of New York, have invented a new and useful Improvement in Electric Slow-Down Devices, of which the following is a specification.

My invention relates to an electric slowdown device, particularly described as employed in connection with a reversible motor controlled from a switch and especially adapted for use with electric elevators manually controlled from the elevator car.

One of the objects of my invention is to prevent the application of the brake until the motor has slowed down to a predetermined speed.

Another object is to provide means Whereby the motor may be rapidly slowed down before the application of the brake.

For the attainment of these ends and the accomplishment of other new and useful objects, my invention consists in the features of novelty in the construction, combination and arrangement of the several parts hereinafter more completely described and claimed in the appended claims.

In the accompanying drawings-Figure 1 is a diagrammatic illustration of my invention as applied to a motor manually controlled from an elevator car controller switch: Figs. 2 and 3 are detail views of the automatic directional switch; Figs. 4 and 5 are detail views of the automatic centrifugal contact device.

Broadly speaking, my invention is operative both to effect a rapid reduction in the speed of the motor from its full speed op-. eration', and to prevent the application of the brake until a certain slow-down speed is attained. If the brake is applied too soon, there is rapid wearing on the brake shoes as well as the jolt-ing and jarring of too sudden stop. The means I employ to obviate these difficulties will be subsequently set forth.

Referring briefly to Fig. 1, the motor M receives current through the main switch S, the automatic switch 0 and the reversing switch R or R. The brake pulley P is shown mounted on the shaft of the motor M and the brake winding B is diagrammatically represented. A driving sheave E is mounted on the motor shaft 13 and a cable these elements will be given before the combined operation is explained.

The automatic directional switch D is preferably attached to one end'of the motor shaft as illustrated by Figs. 2 and 3. In these fi ures the bearings 11 and 12 carry the sha 't 13. A stud bolt 14 is secured in the end of the shaft, and the arm 15 which is provided with a suitable hole is slipped over the stud bolt 14 so that a flat surface is-in contact with the end of theishaft 13. Washers 16 separated by a coil spring 17 p are next slipped over the stud bolt 14 and the locknuts 18 are adjusted so that the arm 15 will be made to bear against the shaft 13 with a certain pressure. A plate 19 is secured to the bearing 12, and this plate"19 supports the contacts 20 and 21, as well as the contact stud 22, all of which are suitably insulated from the plate 19, and are provided with proper means for electrical connection. The arm 15 extends upward between the two contacts 20 and 21, and carries the spring contacts 23 which are insulated from the. arm 15 and are adapted to make electrical connection either with contact 20 or 21. A contact slip 24 and the flexible conductor 25 connect the spring contacts 23 to the contact stud 2-2. The pressure which the spring 17 exerts on the arm 15, is such that as the shaft 13 rotates in the clockwise direction (Fig. 2) the friction of the arm 15 against the shaft carries the arm in that direction too until electrical connection is made between the spring contact 23 and the contact.,21. Similarly, when the shaft 13 is rotated in the opposite direction, electrical connection is made bet-ween the spring contact 23 and the contact 20. v As soon as the springc'ontacts 23 make connection with the contact 20 or 21, the arm 15 ceases to rotate and this connection .is maintained until the shaft 13 is rotated in the opposite directon.

The centrifugal contact device A is shown in detail by Figs. 4 and The spring blades 26 are secured to that portion of the brake pulley P known as the hub by means of the bolts 27, and are insulated from the the various brake pulley P by means of the insulation 28. The contact holders 29, 29 are secured to the free ends of the spring blades 26, the contacts 30, 30' are retained by the contact holders 29, 29 and a conductor 45 is suitably arranged permanently to connect the contacts 30 and 30'.

w A collar 31 is adjustabl secured to the shaft 13 by means of the astening devices 32 and is provided with extending arms 33 which are adapted to provide a support and holder for the slip rings 35 and 36. These I slip rings are preferably made up of two or more sections suitably secured together, and are formed with projecting portions 35' and 36 so located with respect to the contacts 30', 30 that when the said contacts are thrown outwardly from the shaft 13 they make electrical connections with the projecting portions 35' and 36. The slip rings 35 and 36 are insulated from each other and from the collar 31. For convenience in adjusting and removing, the collar 31 may be made up in sections fastened together by the bolts 34 (Fig. 4) and a key 37 and keyway 38 (Fig. 5) are provided for retaining the collar in position on the shaft '13. A packing gland G (Fig. 5) is provided for the shaft 13 where it enters a gear casing which may inclose worm gearing or other drivin mechanism. A support 39 is provided %or holding the brushes 40, 41 in contact with the Sllp rings 36, 35, the brush holder 42 being secured to the support 39 by the bolts 43. These brushes 40, 41 are preferably arranged in pairs (Fig. 4) suitably insulated from each other an from the holder 42, and are provided with electrical connections in the ordinary manner. The sprmgs 44 are adapted to press the contacts 40, 41, against the slip rings 36, 35. Thus it is evident that when electrical connection is made between both of the contacts 30, 30' and the corresponding projectin portions 36', 35', an electrical circuit is c osed from the brushes 40 to the brushes 41 This electrical connection is completed whenever the shaft 13 rotates at a predetermined speed such that the centrifugal action of contacts 30, 30 causes them to 'fiy outwardl and overcome the tension of the spring blades 26. The speed at which this connection is closed may be varied by varyi the size of the contacts 30, 30', or by c an the spring blades 26. The said electnca connection is preferably made at about onethird or one-fourth of full speed, and is broken when the speed falls below that limit.

In order that my invention may be readily understood I shall refer again to Fig. 1 which is a diagrammatic representation of arts of my invention. The contacts of t e controller switch K are so arranged that the contact plate 46 makes connection with the contacts 47 48 and 50 when the hand lever is in the stop or central position, The contact plate 46 will also span the three contacts 51, 52, 47, or 53, 54, 50, but will not'extend to the contact 48 at the same time. When the contact plate 46 is moved toward the central position, contact is made with the contact 48 at the same time the said plate 46 breaks connection with either contact 52 or 54. This is to accomplish a specific result which will subsequently appear.

Let it be assumed that when the hand lever 55 is turned to take the position 55' and the contact late 46, the position 46', the motor M-wi receive current in a way to rotate theshaft 13 in a counterclockwise direction as viewed from the side of the brake. pulley P. When the contact plate 46 makes electrical connection with the contact 53, a circuit is closed from the main 56 through the coil 60 ofthe automatic switch 0 conductor 57 contact 53, contact plate 46, contact 50, conductor 58, to the main 59. This causes the automatic switch 0 to be closed and a circuit to be completed from the main 62, through the winding of the reversing switch R, by conductor 63 and contact 54 to the contact plate 46, and thence to the main 59. As soon as the automatic switch is closed the brake windings B are energized to lift the brake, and energizing the winding of the reversing switch R causes that switc to be closed, thereby completing the circuits to the motor. The rotation of the motor shaft 13 in the assumed direction effects the rotative movement of the. arm 15 until contact 23 makes electrical connection with the contact 20. When the motor M attains a predetermined speed the centrifugal force of the contacts 30, 30- causes them to make electrical connections with the corresponding contacts 36', 35', and to remain in connection therewith until the speed of the motor falls below the predetermined limit.

The various conditions which effect the automatic slowing down and stopping of the motor are described ,as follows :the hand lever 55 of the controlling switch K is turned to the central or stop position. When the contact plate 46 leaves the contact 54 the reversing switch R opens, but the winding of the automatic switch 0 con-- tinues to receive current after connection with the contact 53 is severed, for current is lead from conductor 57, through conductor 64, contacts 36, 30, conductor 45 contacts 30', 35, and conductors 65, 58 to the main 59. As soon as the contact plate 46 leaves the contact 54, electrical connection is made with the contact 48 and the winding of the reversing switch R receives an energizing current, the path of which is traced from the main 62, through the said winding, conductors 66, 67 contacts 20, 23, conductor 68, contact 48, contact plate 46,

contacts 47, 50, and conductor 58 to the main 59. The automatic energization of the reversing switch admits current to the motor M tending to impel it in a direction opposite to its direction of rotation; in other words the motor is slowed down. When the speed of the motor M is reduced to such an extent that the contacts 30 and 30 are not sufiiciently subject to centrifugal action, the circuit through the winding of the automatic switch 0 is opened, and the said switch automatically opens, cutting off all current connections to the motor M, and to the brake windings B, thereby applying the brake to stop the motor.

This invention is particularly applicable to electric elevators and although the controller switch K is separately shown to admit of greater clearness in the drawing, the natural and preferred location is in the elevator car C. The automatic action of this device is such that the car operator is able accurately to judge the distance at which the switch must be operated, to effect the stopping of the car at a certain landing, and this action is effected without subjecting the occupants of the elevator car to the jarring and jolting of a too sudden application of the brake or the hoisting apparatus to the stresses and strains incident thereto.

Thus it is seen that the motor M is slowed down to a certain predetermined speed before the brake is applied. As the action is entirely automatic after the control switch is operated, there is no possibility that the inattention or ignorance of the attendant shall cause the inopportune application of the brake. The same action occurs whether I the motor is operated in one direction or the other, as is plainly evidenced by the symmetrical arrangement of the controlling switch contacts, and the directional switch contacts 20 and 21.

My invention is particularly adaptable to all cases where a gradual stopping of the motor is desirable, without the jarring and jolting of the ordinary stopping.

By this device the brake windings B are energized until the speed of the motor has been gradually reduced to a predetermined value, and then the brake is automatically applied, thus insuring the winding of the motor against burnouts due to the premature application of the brake.

I desire not to be limited to the exact construction combination and arrangement of the several parts as herein described, for it is evident that various changes may be made by those skilled in the art without departing from the spirit and scope of the invention.

ters Patent of the United 1. The combination of an electric motor What I claim and desire to secure by let- States is and a brake therefor, means for connecting the motor and brake to a source of current supply, and means dependent on the speed of the motor for cutting off said supply and applying the brake when the speed of the motor has been reduced to a predetermined value.

2. The combination of an electric -motor and an electromagnetic brake therefor, a switch connecting the motor and brake magnet to a source of current supply, mechanism for effecting a slowing down of the motor, and means controlled by the speed of the motor for automatically opening said switch and applying the brake when the motor speed has been reduced to a predetermined value.

3. The combination of a motor, an auto matic switch, an electro-responsive brake for the motor connected through the said switch, and automatic centrifugal means whereby a holding circuit is closed through the magnet coil of the automatic switch until the ppeed of the motor falls to a predetermined lmlt.

4. The combination of a motor, reversing switches therefor, an automatic electro-responsive switch to admit current to the motor through the reversing switches, an electro-magnetic brake with its magnet winding connected through the automatic switch, and automatic means operated by the motor when rotating whereby the automatic switch opens circuits through the brake magnet winding and the rc ersing switch when the speed of the motor falls to a certain limit.

5. The combination of a motor, reversing switches therefor, a directional switch operated by the motor, and means in connection with the directional switch whereby in stopping the motor from rotating in the direction induced by the closure of one reversing switch, the other reversing switch is automatically closed as soon as the closed reversing switch is opened.

6. The combination of a motor, an automatic directional switch, a centrifugal contact dev1ce in connection with the motor, an electro-responsive brake, means controlled by the directional switch whereby the motor is retarded in stopping, and means in connection with the centrifugal contact device whereby the electro-responsive brake is applied when the motor is retarded a certain amount.

7. The combination of a motor, a manual controller switch therefor, a directional switch operated by the motor in a direction corresponding to the direction of rotation of the motor; means in connection with the said switches, and the motor for automatically reversing the motor circuit connections when said controller switch is moved to position to stop the motor whereby in stopping the motor the path of circuit through the motor is reversed.

8. The combination of a motor, a controller switch therefor, a directional switcli automatically operated by the motor, reversing switches, and means in connection with the controller switch and the directional switch whereby the motor when impelled in one direction by the closing of a reversing switch is retarded after the opening of the said reversing switch by the automatic closing of the other reversing switch.

9. The combination of a motor, a controller switch therefor, a directional switch automatically closed by the motor, electroresponsive reversing switches, and contacts and conductors in connection with the controller switch and the directional switch whereby an energizing circuit is closed through one of the reversing switches when the motor is running at the same time the energizing circuit through the other reversing switch is opened.

10. The combination of a motor, a controller switch, a selective directional switch automatically operated by the motor, electro-responsive reversing switches, means in conjuction with the controller switch and the directional switch whereby one reversing switch, when the motor is running in one direction, is automatically closed at substanliallv the same time the other reversing switch is opened, to reduce the speed of the motor, and automatic means for causing the said closed reversing switch to be opened.

11. The combination of a motor, a directional switch closed when the motor is started, electro-magnetic reversing switches, a controlling switch for the motor comprising electrical connections with the other said switches, said controllin switch comprising a movable contact p ate, and contacts so disposed that when the contact plate is moved from a running position to the stop position a circuit is .clcsed to energize the open reversing switch at the same time the circuit to the then energized reversing switch is opened.

12. The combination of an elevatorcar, a motor therefor, a controller switch in the elevator car, reversing switches, a directional switch automatically operated by the motor, and means whereby the return of the controller switch to its central position when the motor is running automatically energizes one reversing switch at the same time the other is deener ed thereb efi'ecting the gradual reduction in spe of the elevator car. 7

13. The combination of a motor, an elevator can, reversing switches, centrifugal contacts dependent for operation upon the speed of the motor, a controller switch mova le' into position to cause the motor to o rate, and also movable into a stop position, and contacts and circuits. connections associated with the said centrifugal contacts,

whereby when the controller is moved to said sto position current is supplied to the motor t rough one of the reversing switches until the speed of the motor has been reduced thereby to a predetermined limit.

14. In an elevator, the combination of a car, a motor therefor, a controller switch, a directional switch closed b the motor, reversing switches, a centri ugal switch device dependent for operation upon the speed of the motor, circuit connections associated with said parts to supply current to the motor in a direction to retard the motion thereof when the controller switch has been moved to stop position, and an electro-responsive brake device controlled by the centrifugal switch and automatically applied after the motor speed has been reduced.

15. In an elevator, the combination of a motor, 'an automatic switch, reversing switches for producing rotation of the motor in opposite directions, a manual controller switch, a directional switch, a centrifugal contact device, an electro-responsive brake, contacts and connections whereby when the controller switch is turned from a running position to'the stop position the reversing switch which was closed is opened and the other reversing switch is automatically closed, thelatter reversing-switch receiving current through the said automatic switch until the speed of the motor is decreased to a certain limit, said centrifugal contact device being thereupon operative to open the said automatic switch to cut off the current to the motor and to apply the brake.

16. In an elevator, the combination of a car, an electric motor, reversing switches, a controller operable from an initial position to connect the motor through a reversing switch to a source of current supply, and

means for connecting the motor through the other reversing switch to said source of suply when the controller is returned to said initial ositibn.

17. he combination of an electric motor, reversing switch mechanism therefor, a controller operable from a neutral position into position to effect the operation of the reversing switch mechanism and supply current through the motor in either direction, and, means operable when the controller s returned to neutral position to reverse said mechanism and supply current through the motor in the reverse'direction. I

18. The combination of an electric motor, reversing switches therefor, a manual controller operable from a neutral position in either direction to efl'ect the o ration of a corresponding reversing switc and means for operating the other reversing switch when the controller'zis returned to neutral. position. A

means to connect the motor with current a current to the motor in stopping the latter,

an electromechanical brake, and means for cutting off the braking current and applying the electromechanical brake at substan tially the same time.

20. The combination of an electric motor, means to supply a braking current to the motor in stopping the latter, an electromagnetic brake, and automatic means for substantially-*simultaneously cutting off the brake current and applying the electromagnetic brake. 1

21. The combination of an electric motor,

an electroresponsive brake therefor, means 15 for supplying a retarding current to the motor, and means controlled by the speed of the motor for cutting oil the retardingcurrent and at the same time applying the said electro-responsive brake.

In testimony whereof, I have signed my name to this specification in the presence of two subscribing Witnesses.

DAVID L. LINDQUIST.

Witnesses:

EDWARD H. STEELE, GEORGE D. RosE. 

